Series connecting devices for high-voltage power conversion

• Published in: 2007 42nd International Universities Power Engineering Conference pp. 1134 - 1139
• Main Authors: Robinson, F.V., Hamidi, V.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.09.2007
• Subjects: Insulated gate bipolar transistors; Joining processes; MOSFET circuits; Power conversion; Power MOSFET; series connected IGBT; series connected IGCT; series connection; Snubbers; Switches; Switching circuits; Thyristors; Voltage; voltage balancing; voltage sharing
• ISBN: 1905593368; 9781905593361
• DOI: 10.1109/UPEC.2007.4469110

Novel dynamic voltage-sharing schemes have been developed to allow any high-voltage power-semiconductor device, e.g. thyristor, IGCT, IGBT or power MOSFET, to be series-connected in strings, and switched as simply and rapidly in high-voltage applications as single devices. The circuits have many of the advantages of simply using RC or RCD snubbers, including being easily applicable to both low- and high-side switches. However, because the snubber capacitors are not fully discharged their associated reset current and power-losses are minimized. To illustrate the principle of operation experimentally, a string of three series-connected power MOSFETs switching 100 A from 330 V has been used to obtain practical waveforms. The schemes are discussed and illustrated, using SPICE simulation results. The new, relatively simple voltage-sharing schemes are much easier to design and optimize than recently reported active gate-control and regenerative-snubber methods, allow very rapid turn-on and turn-off switching, and give composite- device switches a usable voltage rating similar to the aggregated voltage ratings of the string.